She didn't come back,because she was on a business trip then.
I heard her laughter.
Nobody noticed his leaving.
第二句和第三句的失态也可以用一般现在时。
She didn't come back,because she was on a business trip then.
I heard her laughter.
Nobody noticed his leaving.
第二句和第三句的失态也可以用一般现在时。